過去的十年當中，多角化已成為台灣的銀行業主要發展策略之一。然而文獻關於多角化對於銀行績效的影響，目前似乎尚無定論。因此本研究利用1997-2008年的資料，來探討收入多角化與國際多角化對銀行績效的影響。實證結果發現，台灣銀行業普遍存在國際多角化利益，然而收入多角化對銀行風險報酬的影響並不顯著，增加非利息收入並無法改善銀行風險或報酬，反而會增加收入的波動性或營運成本。我們也發現金控銀行較非金控銀行存在顯著多角化利益，這樣的證據，也可以用來部分解釋為何金控銀行一直追求多角化。

Over the past decade, diversification has become a common strategy adopted by banks in Taiwan. However, the evidence relating to its effect on bank performance varies. Using data from 1997 through 2008, we examine the influence of income and international diversification on bank performance. We find that banks benefit from international diversification, but do not benefit from income diversification. Increasing in non-interest income may increase income volatility and operational costs. We also find that bank holding companies benefit more from diversification than their non-bank holding counterparts. This partially explains why bank holding companies pursue diversification.